Preview

Features

• Animate cell scale while scrolling
• Rotate cell while scrolling
• Easy to integrate and use
• Easy Customizeable

Requirements

• iOS 11.0 +

Usage

Via code

Create a SJCenterFlowLayout object, set its itemSize and assign it to your UICollectionView.

let layout = SJCenterFlowLayout()
layout.itemSize = CGSizeMake(200, 200)
collectionView.collectionViewLayout = layout

via Interface Builder

Set the UICollectionView layout class to SJCenterFlowLayout, and set its itemSize and its properties as given below

Properties

• animationMode (default is scale with sideItemScale between 0 and 1, default is 0.7, sideItemAlpha: between 0 and 1, default is 0.6, sideItemShift: value in pixels, default is 0)

Can be set only through code.

• SJCenterFlowLayoutAnimation.scale(sideItemScale: 0.7, sideItemAlpha: 0.6, sideItemShift: 0.0)

The animation apply following 2 here

1. Scale
2. Rotation

• spacingMode (default is fixed spacing of 40 pts) Can be set only through code.
• SJCenterFlowLayoutSpacingMode.fixed(spacing: CGFloat) Items in the carousel are positioned with a fixed space between them.
• SJCenterFlowLayoutSpacingMode.overlap(visibleOffset: CGFloat) A fixed part of the side items are visible on the sides of the collection (and therefore the space between items depends on the collection size).

Scale Animation (With cells scale animation while scrolling)

• Set the animation mode for collectionview flow layout

centerFlowLayout.animationMode = SJCenterFlowLayoutAnimation.scale(sideItemScale: 0.6, sideItemAlpha: 0.6, sideItemShift: 0.0)

• Set the rotation scale, alpha of collectionView as per your need

Rotation Animation (With cells rotation animation while scrolling)

• Set the animation mode for collectionview flow layout

centerFlowLayout.animationMode = SJCenterFlowLayoutAnimation.rotation(sideItemAngle: 45, sideItemAlpha: 0.6, sideItemShift: 0)

• Set the rotation angle, alpha of collectionView as per your need

Detect current indexPath or page while scrolling

• If you continue to track which current(center) indexPath then use scrollViewDidScroll delegate method. This method called on any offset changes.

func scrollViewDidScroll(_ scrollView: UIScrollView) {
        if let indexPath = centerFlowLayout.currentCenteredIndexPath {
            print("Current IndexPath: \(indexPath)")
        }
        if let page = centerFlowLayout.currentCenteredPage {
            print("Current Page: \(page)")
        }
    }

• After scrolling end with left or right then you can use the scrollViewDidEndDecelerating delegate method. This method called when scroll view grinds to a halt.

// 
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
        if let indexPath = centerFlowLayout.currentCenteredIndexPath {
            print("Current IndexPath: \(indexPath)")
        }
        if let page = centerFlowLayout.currentCenteredPage {
            print("Current Page: \(page)")
        }
    }

Scroll to specifc index

scrollToPage(atIndex index: Int, animated: Bool = true) method use to scroll specific index.

centerFlowLayout.scrollToPage(atIndex: 2, animated: true)

Author

Sandeep Joshi - https://github.com/yudiz-solutions